The photo-fenton reaction and the TiO2/UV process for waste water treatment - novel developments

Solar applications of photochemical waste water oxidation methods driven by UV and/or visible light, especially TiO2/UV and the Photo-Fenton reaction (Fe2+/H2O2/UV-VIS), have been investigated. Degradation results of 4-Chloro phenol and some other model compounds at laboratory scale are discussed. A photoreactor with immobilized TiO2 has led to a higher quantum efficiency t han the suspension treatment. Electron densities were calculated to predict the oxidizing properties of UV irradiated TiO2, Al doped TiO2 powders show ed better performance than undoped samples in laboratory scale degradation experiments. Experiments with different waste waters (e.g. landfill leachat es, plastics industry, etc.) using the Fe2+/H2O2/UV-VIS system in a photore actor prototype are reported. Solar treatment of a model waste water in a g lass basin has been investigated. Furthermore, experiments performed at the Plataforma Solar de Almeria (Spain) with different methods, reactor types and waste waters are compared. According to a comparison of costing the sol ar driven Fenton reaction is a cheap method for water treatment, also for h ighly contaminated effluents. (C) 1999 Elsevier Science B.V. All rights res erved.